Therapeutic lamp



Nov. 19, 1935.

M. MARKS, ALSO KNOWN AS M. M. GINSBERG THERAPEUTIC LAMP Filed July 30,1931 i )fige INVENTOR.

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Patented Nov. 19, 1935 UNITED STATES vPATENT OFFICE 2,0215'runnamszu'rrov Lam Mortimer Marks, also known as Mortimer MathGinsberg, Brooklyn, N. Y.

'Ihis invention relates primarily to therapeutic lamps and is directedmore particularly to a lamp of this character employing an electric arcfor the production of so-called ultraviolet light to be used forthereapeutic treatments and for the so-called sun ray treatments.

Aside from its use in the art of therapeutics, the invention, however,embodies novel and important features relating to the controlling of thefeed of electrical current across a gap to form an arc and this phase ofthe invention is adapted for general application.

In arc lights, considerable diiliculty has heretofore been encounteredin controlling the space between carbons at the arc. 'I'here has been anever present tendency of the movable electrode or carbon when partakingof that movement necessary to draw the arc to overtravel with the resultthat the light has been intermittent and of relatively short duration.

One of the objects of this invention is to control the movable electrodein such manner that when the arc is drawn, this electrode will notnormally move a greater distance from the fixed electrode than isnecessary to produce the desired arc and will be maintained in properarcing relation to the fixed electrode until the electrodes are erodedor burnt away to such extent as will require a feed of the movableelectrode to eect another arcing operation.

An important feature of this invention resides in the fact that theso-called arcing operations are of relatively long duration and are notrapidly intermittent as has heretofore generally been the case, whererelatively fixed and movable electrodes are employed and particularlywhere such movable electrodes have been. controlled by a magnetic fluxcircuit.

Another feature of the present invention resides in time controlledapparatus whereby the duration of operation of the lamp may becontrolled and regulated to the end that the lamp may be set for apredetermined period of operation, to be automatically turned ofi' orde-energized at the conclusion of such period.

In one of its preferred, practical forms, the lamp of this inventioncomprises a fixed and movable electrode, the latter of which is carriedby and supported on the amature of a solenoid which is included incircuit with the electrodes so that the energizing current operates boththe solenoid and causes the arc. 'I'he core of the solenoid is providedwith ratchet teeth disposed longitudinally of the core and with theseratchet teeth cooperates a pawl which conveniently may be made in theform of a leaf spring. The pawl and ratchet arrangement thus providedallows of the feed of the movable electrode in the direction of the xedelectrode, but limits the retrograde movement of the movable electrodeto a distance which will permit the current to normally jump the gap. sothat when the core of a solenoid is energized, the arc is drawn and thespacing of the electrodes at the arc will remain substantially constantuntil b y erosion or burning away the space becomes too great for thecurrent to pass whereupon the movable electrode will be fed by gravityinto contact with the fixed electrode to cause a redrawing of the arcfor a further period of continuous operation. The electrical circuitthrough the solenoid may, according to this invention, include a timeswitch electrically controlled as hereinafter more fully described by anoverload, underload, or weakening of the flux circuit to break theelectrical circuit through the apparatus at the conclusion of apredetermined period of operation.

Features of the invention, other than those adverted to, will beapparent from the hereinafter detailed description and claims, when readin commotion with the accompanying drawing.

The accompanying drawing illustrates diierent practical embodiments ofthe invention, but the constructions therein shown are to be understoodas illustrative, only, and not as defining the limits of the invention.Figure 1 is a central vertical section through a lamp embodying thepresent invention, .this section being taken in the plane of the lineI-I of Figure 2. 35 Figure 2 is a front elevation of the structure'shown in Figure 1, with the addition or a time stage.

Figures 3 and 4 are wiring diagrams showing modified forms of currentcontrol. 40 Referring to the drawing, l indicates a casing which mayconveniently be madeas shown in the form of a reflector across the frontof which is provided a screen 2 for protective purposes. The casing ismounted upon a suitable base I and in the lower portion of the casing isa holder 4 for the fixed electrode 5 which is preferably a conventionalcarbon electrode.

The upper portion of the casing carries a boss 8 in which is supportedan upstanding tubular 50- section 'l and on this tubularsection iscarried a coil l of a solenoid. The tubular section 'I is ofnon-magnetic material such. for example, as brass and it extendsupwardly through the coil I as shown, so as to mount and supportthe'coil 66 thereon. The opposite ends of the coil are preferablycovered with caps 0 and I II which may be either of magnetic ornon-magnetic material, but are, in the preferred form of the invention,of magnetic material, such as soft iron for reasons hereinafter morefully explained.

'Ihe core of the solenoid is indicated at II. It is tubular in form andis provided therein with a bushing I2 insulated from the tubular core byinsulating sleeve I3. The lower end of the bushing is flanged outward ina radial direction while the upper end of the bushing extends above thetubular core and is exteriorly threaded to receive a piece of tubularinsulation I4 which, when screwed down tightly on to the core, willtightly clamp the insulating sleeve I3 in position.

On the inside of the bushing' I2 is a leaf spring I5 and the movableelectrode or carbon Il is adapted to be held resiliently within the coreand its associated parts by frictional engagement with the interior ofthe bushing and with the leaf spring I5. Thus to insert the movableelectrode I6, it is simply forced downwardly through the insulatingsection I4 past the spring I5, whereupon the spring grips the electrodeand holds it firmly in place. The central electrode is thus carried onand supported by the core of the solenoid and is movable axially withsaid core.

The exterior of the core II is provided as shown in Figure l with alongitudinally arranged series of teeth I1 which collectively form aratchet extending for substantially the full length of the core, andmounted upon one of the caps III or in any other suitable and convenientlocation is a pawl I8 shown in the form of a leaf spring. This leafspring is attached to the cap I0 by means of rivets I9 or in any othersuitable way and the nose 20 of the spring extends through a slot 2| inthe tubular section 1 in a manner to engage and cooperate with theratchet Il. The ratchet is so formed as to permit the core to move idlyand freely in a downward direction, but if upon retrograde movement theparticular tooth with which the pawl is juxtaposed will engage with saidpawl and the movement oi' the core in an upward direction will bearrested. If a rigid pawl is used, the teeth of the ratchet should besuillciently far apart to permit a proper arc to be drawn before thepawl arrests the core, but when a spring pawl is used as shown, the slot2I in the tubular section I may be made of such length as to control themovement of the pawl and to thereby cause a positive arrest of the coreafter a predetermined retrograde movement. For example, the nose of thepawl may in normal position be at the lower end of the slot 2 I. In sucha case, the retrograde movement of the core will be controlled by theupper end of the slot because the core will move upwardly and slightlyflex the spring pawl until the pawl engages with the upper end of theslot 2I whereupon further upward movement will be positively arrested.

It it be assumed therefore that the solenoid coil is arranged in serieswith the electrodes 5 and IB as shown in Figure 1, the current which iscaused to pass through the electrodes for the production of the arc willserve also to energize the solenoid, drawing the core upwardly to drawthe arc while the pawl controls the extent to which the core may beretracted for this purpose so that there may be no upper overtravel ofthe core which would result in too wide a 'spacing of Jthe electrodes atthe gap. It will of course be apparent, however, that when theelectrodes burn away or erode sumciently to break the current in thecircuit 22, then-the solenoid will be de-energized and the core willfeed downwardly to present the next tooth to the pawl. 6

The apparatus which I have described as particularly useful intherapeutic lamps, but it may be employed inany arc lighting circuitwithout departing from this invention. Furthermore, there are times whenit would be desirable to 1o have `difi'erent arc lighting circuitsoperate for predetermined periods of duration with subsequent automaticshut ofi'. This is particularly true, for example, in connection withtherapeutic lamps where there is a possibility of serious effects 15 dueto too prolonged treatment. For this reason,

I have provided novel and efilcient means for controlling the time orduration of the operation and in Figure 2, I have shown means foraccomplishing this result. In this figure, the caps l zo and III shouldbe of magnetic material, preferably soft iron. The lower cap is providedwith a bracket 23 to which an arm 24 is pivoted at 2l. This arm is of`magnetic material such as soft iron and the free end 28 of the arm isnormally 9,5 retracted from the cap l by means of a leaf spring 21.Positioned adjacent the inside of the arm 24 is a fixed contact 2l and amovable contact 29. The contact 29 normally tends to move in a directionaway from the contact 28, so that when the arm 24 is swung outwardlyaway from the cap 9, the contact 29 will disengage from the contact 2l.The contacts 28 and 29 are included in the circuit which includes theelectrodes and the solenoid coil. Thus, when these contacts areseparated, the circuit will be deenergized.

The theory of operation of the structure shown in Figure 2, is th'atwhen the core of the solenoid is near or adjacent its magnetic centerwithin 40 the coil, the magnetic ux circuit of the solenoid willcomprise the soft iron core, the cap 9, arm 24 and the lower cap III, sothat there will be a substantially closed flux circuit to the solenoid.As long as this flux circuit is strong enough to u overcome the tensionof the spring 21, the arm 24 will be held in the position shown in Fig.2 by the flux circuit. However, as the lamp operates and the core feedsdownwardly through a period of time, there will come a time when thecore 50 will be moved downwardly so far away from the upper cap 9 as toso weaken the flux circuit that it will no longer be strong enough toretain the arm 24 in this position and thereupon the spring 21 willthrow the arm in an outward 55 direction and break the circuit at thecontacts 28 and 28, thus de-energizing the entire lamp.

My experience has shown that the erosion or burning away of theelectrodes occurs at a substantially uniform rate, so that it can bewell w determined how. long a predetermined portion of the length of theelectrode will be consumed within a predetermined period. Thus byattaching to the core or to the electrode an adjustable indicator 30 andproviding a time scale 3| over g5 which this indicator may travel, it ispossible to initially set the parts so that the lamp will function for apredetermined time at the expiration of which the core will have moveddownwardly far enough to release the arm 24 and 7 shut off the lamp.

Another way in which the timing of the operation may be accomplished isshown diagrammatically in Figure 3. In this figure, an overload releaseindicated at 32 is included in the circuit n in series with the carbonsand the solenoid.

the armature descends to a certain point, thev magnetic pull isinsumcient to support the weight of the core or armature. When thisoccurs, the carbons meet but no arc is drawn. As the carbons remain incontact, the voltage drop across the carboneis practically eliminatedand the heavier current which is thereby caused to now may be utilizedto operate any well known and suitable form of overload release switch.indicated at Il. whichis included in the'circuit ci' the lamp. Thetiming is accomplished by the height oi the amature at the commencementoftheoperation,sothatitwilltakeacertain length oi.' time for the carbonsto burn away and permit the armature to descend to the critical pointwhere the carbons will meet. but the magnet will be oi insuilicientstrength to raise the armature. Almost immediately the overload releasewill operate and the feed oi current through the apparatus will cease.

Most of hand operated therapeutic arc lamps now in use utilize ilxedelectrodes set at an angle asshowninFigure4. Ihaveioimd thatIcan timethe operation of such a lamp by using an underload release switch asshown in this 1181111. The switch arm is pivoted at Il and constitutesthe armature oi magnet Il. A spring Si, the tension ot which may beadjusted by a set screw acts to normally retract the arm Il from themagnet core 35. When the current has burned away, the carbons to, e. g.,the line Il, the cur-v rent in the circuit will have been suillcientlydecreased to decrease the pull oi' the magnet Il on the arm n which willbe acted upon by spring 36 to break the circuit. The timing may becontrolled or determined by regulating the tension -oi the spring 36 soas to draw the handle away after the current has decreased to spredetermined extent. Since the burning oi' the carbons is at asubstantially uniform height, I may thereby obtain approximately correcttiming.

Having thus fully described tli'e invention, what I describe as new anddesire to secure b Letters Patent is:

1. In an apparatus oi the character described, a solenoid having a core.a rmovable electrode carried by the core, a stationary electrodepositioned to cooperate with the movable electrode to permit oi' theformation ot an arc therebetween, ratchet teeth carried by the armature,and a pawl mounted in relatively stationary position and adapted tocooperate with said ratchet teeth to permit the unrestricted ieed of themovable electrode in the direction oi' the fixed electrode, but to limitretrograde movement o! the movable electrode to a predetermined maximum;

2. In an apparatus of the character described, relatively iixed andmovable electrodes, a solenoid having a core on which the movableelectrode is supported, and pawl and ratchet means ior permitting thefeed oi the movable electrode in the direction oi the nxed electrode butto limit retrograde movement oi' the movable electrode to apredetermined maximum.

3. In an apparatus of the character described, ilxed and movableelectrodes. a solenoid core secured to and supporting the movableelectrode, said core provided with a series o! ratchet teeth, a solenoidcoil surrounding said core for energizing the same and a pawl mountedstationary with respect to the coil and coacting with the ratchet teethot the amature to permit the armature to iced the movable electrode inthe direction oi' the nxed electrode but to limit the retrogrademovement oi the movable electrode to a predetermined maximum.

4. In an apparatus oi the character described.l s relatively movableelectrodes withl means i'or moving them apart ior the purpose ot drawingan are between them. and pawl and ratchet means for restricting theseparating movement of the electrodes to a predetermined maximum. 1o

5. In an apparatus oi the character described, nxed and movableelectrodes, an armature :secured to and carrying the movable electrode,a coil for operating said armature to move the movable electrode for thepurpose oi drawing l5 an are, pawl and ratchet means cooperating withthe armature to limit the gap .between the electrodes to a predeterminedmaximum, an electric circuit including the electrodes and the coil. anda switch included in said circuit, and an overlo load relay switchincluding said circuit.

6. In an apparatus oi' the character described.

a solenoid comprising a core and a coil. the latter oi' which isprovided at its opposite ends with magnetic parts adapted to iorm withthe 25 core a portion oi a i'lux circuit, a magnetic bridge memberadapted to normally bridge said magnetic parts to form with the metallicparts and core a magnetic ilux circuit when the core is at or adjacentits magnetic center within the coil, an electrode carried by said core,a circuit ineluding the coil and electrode, a switch also included insaid circuit, and positioned to be operated by the magnetic bridge, andmeans for retracting the bridge from engagement with one o! the magneticend pieces oi' the coil, and opening the switch when the core descendsappreciably below its magnetic center.

7. A therapeutic lamp embodying a pair oi relatively movable electrodes,an armature ior caro rying one oi them, an electric circuit includingsaid electrodes, and means amxed to the armature electrode to permit theshifting oi the said electrode relative to its armature ior the purposeot eilecting timing. and a time scale 45 cooperating with said means.

8. A therapeutic lamp embodying a pair o! relatively 'movableelectrodes, electromagnetic means for shitting one oi' said electrodeswith respect to the other for the purpose oi draw- 50 lng an arc withconsequent erosion of the electrodes, said electromagnetic meansincluding a coil and an associated armature by which armaturefone ofsaid electrodes is carried, a circuit including said coil andelectrodes, means also 55 included in said circuit for breaking thecircuit when the armature is sumciently remorved, through continuederosion oi the electrodes, from the magnetic ilux circuit to cause apredetermined weakening of such ilux circuit, and manually ops0 erablemeans tor axially shifting one ci said electrodes in a direction toreturn the armature to substantially the magnetic center of the coil.

9. A therapeutic lamp embodying a pair ot relatively movable electrodes,electromagnetic means 66 for shifting one oi said electrodes withrespect to the other for the purpose of drawing an arc with consequenterosion oi the electrodes, said electromagnetic means including a coiland an associated armature by which armature one o! 'l0 Isaid electrodesis carried, a circuit including said coil and electrodes, means alsoincluded in said circuit for breaking the circuit when the amature issuiliciently removed, through continued erosion oi the electrodes, iromthe mag- 15 netic ux circuit to cause a predetermined weakening of suchiiux circuit, manually operable means for axially shitting one of saidelectrodes in a direction to return the armature to substantially themagnetic center of the coil, and a. time scale associated with saidmanually operable means for the purpose of regulating the electrodes andamature to such relation as will permit of a. predetermined elapsedperiod of time oi' operation before the amature has moved into aposition to cause said circuit breaking means to break the circuitthrough the coil and electrodes.

MORITMER MARKS, Also Known as Mortimer Marks Ginsberg.

